Manufacturing and production industries use automatic test equipment (ATE) to analyze and assess integrity and operability of manufactured products at various stages of production. Robotic manipulator machines are often employed during testing by ATE to manipulate workpieces and products into and out of connection with the ATE. The devices under test (DUTs) are presented to a test site of the ATE by the robotic machine, tested by the ATE, and then sorted and dispensed by the robotic machine into groups or bins (or otherwise according to applicable scheme) according to test results.
The ATE typically includes a system controller which controls the ATE and movement of data into and out of the ATE. The ATE also includes test data and test program storage, pattern memory, system power supplies, direct current reference supply unit, analog current reference supply unit, system clocks and calibration circuits, timing and timeset memory, and precision measurement unit (which may include digital, analog or mixed signal test resource circuitry). In addition, a test head of the ATE includes pin electronics driver cards providing pin circuitry (such as for comparators, current loads and other test resources) for pin electronics testing of DUTs. Conventionally, a device interface board (DIB) (also referred to as “load board) connects to the test head via respective tester pins of the ATE corresponding to the respective pin electronics and pin circuitry, and includes one or more test socket for the DUTs for testing by the ATE. The ATE also includes external interfaces for connection to robotic manipulators for test devices (referred to as “handlers” or “device handlers”), as well as interfaces to computers, networks, and/or other instruments, devices or components.
Robotic manipulators, i.e., handlers, include mechanical systems and handler controllers. Conventionally, the mechanical systems physically deliver DUTs for connection to the socket(s) of the DIB connected to the test head of the ATE, deposit the DUTs in the socket(s) during testing, remove the DUTs from the socket(s) post testing, and sort the DUTs according to respective test result after testing. For a group of DUTs to be tested by the ATE, the handler controller directs operations of the mechanical systems of the handler and communicates with the ATE to successively transfer and connect DUTs for test, remove them post test, and retrieve next DUTs of the group for handling in same manner, until all DUTs of the group are tested by the ATE. As required, handlers can include additional features of memory and specific units according to application and testing environment.
Because many diverse types of DUTs are tested by ATEs, and DUTs may be tested at various stages of production (e.g., final test, workpiece probe, etc.), ATEs (including wafer probers) are varied in design according to particular purpose and device or product for testing. Similarly, robotic manipulator machines vary according to application and compatibility with the ATE. A particular variation among ATEs is the mechanical docking required for precisely connecting tester pins of the ATE to DUTs presented to the ATE by the robotic manipulator machine for the DUTs.
ATEs are typically of a “hard dock” (or “hard docking”) type or of a “soft dock” (or “soft docking”) type:
Hard docking is direct mechanical connection of the robotic manipulator machine to the ATE at the test head for precise placement of DUTs by the robotic machine in test sockets of the DIB connected to the test head. Hard docking has been desirable, for example, in the case of higher frequency testing and testing of complex or mixed-signal devices, because connection of the robotic machine to the ATE at the test head limits DUT and device interface board component stress that can be otherwise caused in operation of the robotic manipulator equipment where not precisely aligned at the ATE test head. Hard docking has also been desirable for test signal integrity between the test head and the DUTs positioned by the robotic machine, as well as to avoid undue vibration or other affects that may vary testing for successively positioned DUTs retained in test sockets during testing by the robotic manipulator equipment. Hard docking, however, requires particular positioning (within allowable test floor space) of ATE and robotic manipulator equipment and units. Moreover, extensive setup steps and requirements, for example, alignment by bars, guide pins, cam and/or vacuum lock, must typically be performed and validated for hard docking Extensive component changes may be necessary when switching ATE test head features or robotic manipulator equipment types.
Soft docking, on the other hand, is indirect mechanical connection of the robotic manipulator machine to the ATE, for example, by flexible cabling and interfacing devices, rather than direct mechanical connection as in hard docking Rather than mechanical alignment of the ATE and the robotic manipulator equipment, cables and intermediate interfaces from the ATE serve as connectors which can be located relative to the robotic equipment. Soft docking generally provides greater flexibility for test floor location of the robotic manipulator machine with respect to the ATE, allowing greater variability in location of equipment/units and use of test floor space. Moreover, soft docking can provide easier switching of ATE test head boards and features and of different robotic manipulator equipment types. Because soft docking does not directly mechanically connect the ATE and handler, however, test signals of the ATE are communicated via non-rigid cables coupled with interface device(s) during testing. For higher frequency tests, testing of complex devices, and certain other testing processes, indirect connection via soft docking can present problems, such as affects on test signal integrity, calibration and equipment. For example, test signals reaching soft docked test sockets pass through intermediate connector cables and interface devices between the ATE and test sockets (with consequent affects on the test signals) often vary significantly from actual test signals at the ATE. More extensive calibration efforts can be required because all intermediate connectors, as well as additional calibration equipment, steps, and features, can affect the test signal. Furthermore, test signal interference in soft dock configurations can result from environmental conditions (electrical, mechanical, magnetic, vibration, etc.) and changes in environment when test signals pass through intermediate connector cables and interface devices. Because no direct mechanical connection exists between the ATE test head and the robotic equipment in soft docking, connector cabling and interface devices are subjected to more stresses resulting in wear and damage. Depending on the particular testing by the ATE (e.g., test signal frequencies, timing and other characteristics), the tests may not be suitable for soft docking configuration because of limitations presented for distances, numbers and extents of intermediate cabling and interface devices of soft dock configuration.
It would, therefore, be advantageous to provide universal docking systems and methods for connecting automatic test equipment and robotic manipulator equipment. It would also be advantageous to eliminate or reduce problems that have been presented in hard docking and in soft docking It would further be advantageous to provide universal systems and methods for multiplexing robotic equipment, for example, more than one handler, in connection to test equipment. Therefore, universal docking systems and methods for multiplexing robotic manipulator equipment connected to same automatic test equipment, with other advantages, would be a significant improvement in the art and technology.